Adjustable boring-tool



F. P. LOVEJOY.

ADJUSTABLE BORING TOOL. women FILED MAY 3, 1911.

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M w? m 1 5% FRED r. LovEJoY, or SPRINGFIELD, VERMONT.

ADJUSTABLE BORING-TOOL.

Specification of Letters Patent.

Patented Sept. 23, 1919.

Application filed. May 3, 1917." Serial No. 166,147.

To all whom it may concern Be it known that I, FRED P. LOVEJQY, a citizen of the United States, residing at Springfield, in the county of Windsor and State of Vermont, have invented new and useful Improvements in Adjustable Boring- Tools, of which the following is a specification. e

The object of the present invention is to provide an improved boringtool comprising a cutter, a holder therefor, and means for fastening the cutter to the holder in various positions of adjustment.

The cutter may be made of relatively high grade and expensive steel, while the holder therefor may be made of less'expensive steel with a view to economizing in the quantity of the more expensive grade of steel. Whenever a cutter becomes so far worn away by use and resharpening that it cannot be used again a new cutter may be substituted for it.

The means whereby the cutter is fastened port after once having been set in operative position.

Of the accompanying drawings that illustrate the invention in what I now consider the preferred form:

Figure 1 represents a top plan view including a portion of a holder, a cutter arranged in said holder, means for fastening the cutter to the holder,and broken lines representinga piece of work undergoing a boring operation by said cutter.

Fig. 2 represents an elevation of the tool shown by Fig. 1, viewed in a line parallel to line 33 of Fig. 1. This figure is inclined to facilitate projection from Fig.1.

Fig. 3 represents a sectional view through the structure intersectedby line 3- 3 of Fig. 1, excepting that the cutter is. shown in elevation.

Fig. 4 represents an elevation of thelocking shoe that coacts with the cutterto adjust and lock the latter relatively to the holder. 7

Fig. 5 represents an'elevation, on a larger scale, of the adjusting screw and indexing pin included in Fig. 2.

Fig. 6 represents a sectional view through the cutter. and holder in the plane indicated by line 66 of Fig.2, the locking shoe and at right angles to its axis.

, adjusting screw being represented in elevationr Fig. 7 represents a cross-section through the structure intersected by line 7- 7 of Fig. 6.

The same reference characters indicate the same parts wherever they occur.

The .cutter is indicated at 10 and the holder therefor is indicated at 11. In the present instance the cutter is cylindric excepting that it is provided on one side with a series of ribs or teeth 12 that extend nearly The holder 11 is provided with a cylindric socket 13 for the cutter, so located at an angle to the axis of the holder, that the cutter projects laterally and forwardly from the corner formed by the end face and the periphery I when it is locked inone position by means hereinafter explained.

The holder .is provided with a cylindric socket 14 thatintersects the socket 13, the axes of the two sockets being substantially at right angles to each other although offset one from another as shown by Figs.

, 2 and 6. A looking shoe 15 is arranged in socket 14, and is provided with ribs or teeth 16 that coact with the ribs or teeth 12 of the cutter, .to sustain the end-thrust of the cutter and to lock the cutter relatively to the holder. The shoeis cylindric excepting on the side that has the teeth 16. The axis of the shoe is indicated by lines aa in Figs. 1, 4, and 6. As shown by Fig. t the ribs or teeth 16 are inclined relatively to the axis, injconsequenee ofwhich endwise movement of the shoe will cause endwise movement of the cutter. This inclination of the teeth, and the consequent capacityof the shoe to impart endwise movement to the cutter are. utilized to adjust the latter relatively to theholder, as hereinafter described.

vanced toward the spring 17 its teeth 16 re tract the cutter slightly, the degree of retraction depending upon the angle of inclination given to the teeth 12 and 16. An adjusting screw 18 is then screwed into socket 14, the latter being provided with an internal screw thread 19 for this purpose. As the screw is advanced 1t advances the shoe 15 and the compresslon spring 17, the compression of the spring beenough to move the shoe 15 in the opposite direction when the adjusting screw 18 is unscrewed.

' Screw 18 is provided with a cylindric head 20 and the latter is provided with a slot 21 for the reception of a screw driver with which to operate the screw. The device may include an index or gage for 1n- .dicating. the degree of rotative movement imparted to the screw. Such gage in the present instance comprises an index pin 22,

and a series of marks such as lines 23 in the periphery of the head 20. The index pin 22 is set into the holder 11 (see Fig. 2) and its outer end, which is within the perimeter of said holder, is beveled so that it will cooperate conveniently with the lines "23.

Under some operating conditions there is excessive vibration or chattering of the tool, and in such cases the adjustlng screw 18 may recede in consequence of the pressure exerted against it by spring 17. In order to overcome such movement on the part of the adjusting screw I provide a friction ring 24,

. and form a circular groove 25 in the thread- 7 1 ed portion of the screw, for the reception of though it need not comprise more than one said ring. The ring is made of spring wire and is preferably of hellcal formation, al-

convolution. One end of the ring is bent inwardly toward the center as indicated at 26 in Fig. 7. The screw 18 is bored radially to provide a socket 27 for the reception of the end 26, the ring being thereby anchored to the screw so as to partake of all rotative movement lmparted to the screw. The helical formation of the ring coincides with the leading of the screw thread, and the normal diameter of the ring is such that the ring requires slight compression in order to screw it into the internal thread 19. The

firing therefore tends constantly to expand against the internal thread, and the friction due to such tendency prevents it from turning excepting when a considerable rotative force is applied to the screw. Inasmuch as the ring is anchored to the screw the latter cannot turn without turning the ring, and the screw is thereby held in any position of adjustment without liability of being moved from its position by any cause other than intentional adjustment with a screw driver.

I claim:

1. A metal-working tool comprising an elongated cutter, a holder having an elongated socket arranged at an oblique angle thereto and adapted to receive said cutter with the cutter projecting laterally and longitudinally beyond the end of the holder, said holder having a second elongated socket extending inwardly from its side and inters'ecting the cutter socket, a shoe adapted to move endwise in said second socket, said shoe and said cutter having interlocking teeth arranged to sustain end-thrust of said cutter, said teeth being inclined slightly to the axis of said shoe to cause relatively slight endwise movement of said cutter in consequence of greater endwise movement of said shoe, and means carried by said holder accessible and arranged to impart endwise movement to said shoe.

2. A metal-working tool comprising an elongated cutter, a holder having an elongated socket arranged at an oblique angle thereto and adapted to receive said cutter with the cutter projecting laterally and forwardly, said holder having a second elongated socket extending inwardly and forwardly from the side thereof and inter secting the cutter socket, a shoe adapted to move endwise in said second socket, said shoe and said cutter having interlocking teeth arranged to sustain end-thrust of said cutter, said teeth being inclined slightly to the axis of-said'shoe to cause relatively slight endwise movement of said cutter in consequence of greater endwise movement of said shoe, a spring carried by said holder at the inner end of the'second-mentioned socket and arranged to move said shoe endwise in one direction, and a screw in alinement with said shoe and carried by said holder and arranged to move said shoe in the opposite direction.

'3. A metal-working tool comprising an elongated cutter, a holder having an elon gated socket adapted to receive said cutter and to hold it with its cutting end beyond the end of theholder, said holder having a second elongated socket formed in the side thereof and intersecting the cutter socket, a shoe adapted to move endwise in said second socket, said shoe and said cutter having vinterlocking;teeth arranged to' sustain endthrust of said cutter, said teeth being inclined slightly to the axis of said shoeito cause relatively slight endwise movement of said cutter in consequence of greater endwise movement of sa1d shoe, a helical compresslon spring arranged in said socket to act on one end of said shoe, and a screw accessible from the side of the holder and arranged to act on the opposite end of said shoe toadvance the latter against the stress of said spring. 7

4. A metal-working tool comprising an elongated cutter, a holder having an elongated socket adapted to receive said cutter, said holder having a second elongated socket intersecting the cutter socket, a shoe adapted to move endwise in said second socket, said shoe and said cutter having interlocking teeth arranged to sustain end-thrust of said cutter, said teeth being inclined slightly to the axis of said shoe to cause relatively slight endwise movement of said cutter in consequence of greater endwise movement of said shoe, a spring carried by said holder at the inner end of the second mentioned socket and arranged to move said shoe endwise in one direction, a screw in the second mentioned socket and arranged to move said shoe in the opposite direction, and an index element aifixed to said holder in contiguous relation to said screw, the latter having a circular series of indicating marks arranged to coact successively with said index element as the screw is turned.

5. A metal-working tool comprising a holder having two elongated sockets intersecting each other, a cutter arranged in one of said sockets, a shoe arranged in the other one of said sockets, said cutter and said shoe having interlocking teeth arranged to sustain end-thrust of the cutter, said teeth being inclined slightly to the axis of said shoe to cause endwise movement of the cutter in consequence of endwise movement of the shoe, a screw carried by said holder and arranged to impart endwise movement to said shoe, said holder having an internal screw-thread coacting with said screw, said screw having a reduced portion, and a helical spring surrounding said reduced portion and bearing agalnst said internal screw-thread With pressure in a direction away from the axis of said screw, one end of said spring being anchored to said screw to hold the latter against rotation relatively to the spring.

In testimony whereof I have aflixed my signature.

FRED P. LOVEJOY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

